Synths that were used in these songs?
Material Girl: sine/triangle wave pad, synth bleep, guitarish sawtooth lead. Edit: apparently it was a bass guitar for the bass. The sawtooth lead is a synth with a modulation wheel or lever or button.
King Tut: pulse wave portamento lead.
Holiday: duophonic-sounding synth meow sound (I might have seen it played on an Odyssey by ARP (Mark I).
Material Girl is on this video:
And Holiday is on this:

Last edited by Music Bird on Sun Nov 15, 2015 9:41 pm, edited 3 times in total.

Also: what was used on Bucks Fizz Land of Make Believe? Especially the octave synth.
What Korg polysynths were around in 1984 (I saw a song from then which was my first time seeing a Korg from the 80s being played live other than a M1